Hi, Tolunay Thank you for your suggestions.
I am the maintainer of CSB272 port of U-Boot. I've done the port based on technical info of the board which is not very reliable. Unfortunately, Cogent generally is not very responsive to emails regarding the ambiguous/outdated technical information about their boards. Some information is extracted by using BDI2000 after uMon intitialized the hardware. Some information is based on datasheet of the parts.
This is actually a discontinued board. In our application here, we do not use the Epson controller. We have switched to using CSB472 now which is smaller and does not have the parts we do not use.
Since we have chosen this board and I have to solve this problem.
On 8 Sep 2004 at 22:23, Lonsn wrote:
then bootm, kernel panic at init EPSON1356 Display Controller, so I reset U-BOOT, I download kernel again
To me it sounds like your Epson1356 driver issue in Linux kernel. You should debug the driver to find out what exactly within the driver is causing the panic.
Check the assumptions made by the driver. The particular driver may be assuming that bootloader is doing a particular initialization however a well written driver should not assume these and re- inititialize the hardware suitably. It could also be a race condition or an uninitialized variable.
I will try to do it.
Should I pay attention to SDRAM init sequence in U-BOOT as Wolfgang has said many times?
As far as I know SDRAM initialization for CSB272 is correct. The information supplied by Cogent in the tech. documentation is for 32MB SDRAM (older) version of the board but your and my board are 64MB.
I also compared the sdram init code between U-BOOT and uMon, there aren't much differences except uMon delay 10ms after enable the memory bank at last. So I think it's not the question of sdram init.
I will check the epson driver in kernel.